A Simple Preparation Method of Reduced Graphene Oxide-Incorporated BiVO4 Loaded with CoOx Composites and Application to Z-Schematic Water Splitting under Visible Light Irradiation

The construction of Z-scheme systems is an efficient strategy to realize water splitting under visible light irradiation. In particular, various photocatalysts can be employed for Z-scheme systems when a reduced graphene oxide (RGO) is used as an electron mediator. Herein, a simple 1-step process for the preparation of RGO-(CoOx/BiVO4) composites is developed. In the developed preparation method, Co ions are oxidized to CoOx by photogenerated holes in BiVO4 accompanied by simultaneous reduction of GO to RGO by photoexcited electrons. The developed preparation method is simpler than a conventional method that contains loading with CoOx by impregnation and subsequent incorporation of RGO by photocatalytic reduction. Z-schematic water splitting under visible light irradiation proceeds when RGO-(CoOx/BiVO4) prepared by the 1-step process is combined with Pt/(CuGa)(0.5)ZnS2. Moreover, the developed method is also able to be applied to the preparation of RGO-(FeOx/BiVO4) composites.